Looks can be deceptive. If you want some proof, consider a new study which analyzes the actions of aggressive-looking males. Turns out, men with angry, violent faces are actually far more likely to makes sacrifices for their close friends.

The research, carried out by a pair of psychologists at St Andrews University, Scotland and published in Psychological Science, investigated the generosity of individuals with differing face shapes.

In the past, plenty of research has shown that the width-to-height ratio of the human face correlates with antisocial tendencies like aggression, exploitation, cheating, and deception. The wider a person's face for a given height, the more likely they are to behave anti-socially.

This new research, however, suggests that the same measurement also correlates strongly with in-group generosity. So, amongst a group of friends or family, those with proportionally wider—for which read, more aggressive—faces are also the most likely to make sacrifices for other members of the group. Not just that, but they also put the well-being of their group above that of themselves.

The researchers claim that the finding makes evolutionary sense: the most aggressive members of a group also have a strong desire for it to succeed and, seemingly, will do whatever it takes to achieve it. [Psychological Science via Daily Mail]